I have a text field on my site which is becoming a problem. Users tend to input more text than I had expected. I need to convert this text field into a long text field. This is problematic because there is already content. I'm looking for a way to do the conversion as painlessly as possible. Here is my current plan:

Create the new long text field

Use a module (probably feeds) to duplicate the data (export, then re-import)

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

I had to do this recently, and tried to follow this tutorial, but I got errors (you can see my comment there, which is the latest one). I ended up creating the new long text field and then just copying over the values from the old field in the database using PHPMyAdmin. It was relatively painless.
– Ben McCloskeyApr 10 '14 at 3:14